Some electronic devices emit electromagnetic radiation. To prevent deleterious interference of electromagnetic radiation upon other electronic equipment, limits are placed on the permissible amount of electromagnetic emissions from electronics equipment enclosures housing electronic devices. To comply with these limits, enclosures are typically sealed and made of an electrically conductive material (i.e., shielded). Invariably, one or more apertures are provided for accessing the electronic devices or boards housed therein. To prevent such EMI/RFI leakage at these apertures, an electrically conductive seal is needed to preserve the shielding integrity of the equipment enclosure.
Modular design approaches incorporate replaceable plug-in modules that can enhance or otherwise adapt features of a given electronics equipment enclosure. A modular design is particularly advantageous when plug-in modules are widely available. One class of such widely available modules conforms to a standardized form factor known as the Peripheral Component Interface (PCI) form factor. These PCI modules are often used in applications to provide customizable features, such as communication interfaces, to an equipment enclosure.
Some plug-in modules, including those subscribing to a PCI form factor, include an electrically conductive mounting bracket attached along an outer edge of a printed circuit board. The mounting bracket serves as a mechanism by which the plug-in module may be secured to a panel of the electronics enclosure after the plug-in module is seated therein. Usually, the mounting bracket has ports through which external devices can communicate with the printed circuit board. For the ports of the mounting bracket to be externally accessible, the mounting bracket is typically secured to an exterior panel of the electronics enclosure. The exterior panel has a slot-shaped aperture dimensioned to accommodate the mounting bracket. After being attached to the exterior panel, the electrically conductive mounting bracket should seal the slot-shaped aperture to prevent electromagnetic radiation from escaping the electronics enclosure.
In addition, the printed circuit board of the plug-in module usually has an edge-style or a finger-style connector, for mating with a connector within the electronics enclosure. Depending upon the location of the connector in the electronics enclosure, the mounting bracket may need to be moved within the electronics enclosure in order for the connector of the printed circuit board to mate with the connector of the electronics enclosure. However, many standard mounting brackets, including those used with PCI plug-in modules, have a perpendicularly angled flange; and this flange projects through the slot-shaped aperture. To accommodate the outwardly projecting flange while being able to move the printed circuit board to mate the connectors, the slot-shaped aperture may need to be larger than the mounting bracket. Accordingly, when the connectors of the printed circuit board and electronics enclosure mate, an uncovered section of the slot-shaped aperture may remain through which electromagnetic radiation can leak.